News / A new age of sail – but not for deepsea containerships, says bound4blue

Photo: bound4blue

Bound4blue has announced another sail installation on a shortsea vessel, as car carriers and general cargo vessels also prepare for a new age of sail.

But containerships remain the odd one out, missing out on huge fuel savings at time when they are sorely needed to meet incoming EU tax regimes.

Shortsea general cargo operator Amasus has agreed to install a bound4blue suction sail on a second vessel, whose rendering bears some resemblance to H&S Fairness, a 2,900dwt vessel in the fleet.

Instead of the side-by-side 17-metre suction sail setup on Amasus’s Eems Traveller, the new installation, due at Astander Shipyard in Santander in 2025, will incorporate a single larger sail, 22 metres in height.

This decision might have been based on a new aerodynamics model bound4blue has created to simulate ‘interference’ between nearby sails, something affecting Eems Traveller, explained CTO David Ferrer this week.

“There are two sails very close together and our model was not ready at the time of this installation. Of course, if you can’t avoid that interference, you have to live with it,” he said.

But this interference is currently prohibiting sails installation on containerships, where high stacks of boxes eliminate the usefulness of any device at deck height.

And while car-carriers and flat-top general cargo and shortsea vessels will be able to benefit from considerable fuel savings throughout northern Europe – partially mitigating onerous ETS costs – deepsea containerships will not be able to claim the same benefits.

“I’ve seen proposals where we take one corner of containers so we can put the sail there, but if it’s covered on two sides, what’s the point? So you have to put it really high up,” explained Mr Ferrer.

“You could [put sails on top of the bridge]… but on a 300-metre vessel, only having one sail, this is not so easy. These vessels have containers fore and aft of the bridge, which creates an obstacle [for STS cranes].”

A further problem for designers of suction sail technology is that it is easy for other manufacturers to copy.

“We take for granted that we’re going to be copied,” said Mr Ferrer. “Even if you build outside China, you bring it to China, [and it’s] really easy to copy. They can copy the structure and shape.

“That’s why we put a lot of effort into aspects that are harder to copy – how to trim the sail differently to minimise the interference, how the sails are controlled, angle of attack, the suction power you need. We are secretive about these aspects.”